Property and Equipment
 12 Months Ended
Dec. 31, 2015
Property, Plant and Equipment [Abstract]  
Property and Equipment
5. PROPERTY AND EQUIPMENT

Property and equipment consisted of the following:

 

     As of December 31,  
     2015      2014  

Office equipment

    $ 539       $ 467   

Laboratory equipment

      4,337         2,978   

Leasehold improvements

      7,683         7,503   

Construction in progress

      547         270   

Software

      96         35   
  

 

 

     

 

 

  

Total property and equipment

      13,202         11,253   

less: accumulated depreciation

      (7,989 )       (6,375 ) 
  

 

 

     

 

 

  

Property and equipment, net

    $ 5,213       $ 4,878   
  

 

 

     

 

 

  

Depreciation expense related to property and equipment amounted to $1,614 and $726 for the years ended December 31, 2015 and 2014, respectively.